**Author Listing - Lead/ Submitting Author (we will be communicating with this individual): Name, Institution, City and State where the work was done. Co-authors will be added in a separate section.**
Dipan Uppal, Cleveland Clinic Florida, Weston, FL

**Main Body of the Abstract**
Background: Transthyretin cardiac amyloidosis (ATTR-CA) is most often associated with heart failure with preserved ejection fraction (HFpEF). The incidence of ATTR-CA in patients with lower ejection fractions is not well characterized.
Methods: We performed a single-center retrospective cohort study of consecutive patients with ATTR-CA evaluated between 02/2016 and 12/2022. Data on patient demographics, comorbidities, imaging, and laboratory findings were compared across HF phenotypes.
Results: Our registry contained 213 patients. 21.6% (n=46) presented with heart failure with reduced ejection fraction (HFrEF), 17.8% (n=38) with heart failure with mid-range ejection fraction (HFmrEF), and 60.6% (n=129) with HFpEF at the time of diagnosis with ATTR-CA. The mean age was 78.1± 8.6 years with 91.1% male. Comorbidities included hypertension (78.9%), ischemic heart disease (55.9%), atrial fibrillation (72.8%), and chronic kidney disease (63.4%). Half presented with a NYHA class ³ III at the time of diagnosis. Those presenting with HFrEF or HFmrEF were more likely to have NYHA functional class ³ III (p=0.003), higher NT-pro-BNP (P=0.001), and higher serum creatinine levels (P=0.02) as compared to those with HFpEF. Additionally, with the decline in systolic fraction, end-diastolic left ventricular internal diameter increased significantly (P<0001).
Conclusion: Although ATTR-CA is traditionally thought to be seen primarily among patients with HFpEF, our data suggests that ATTR-CA has a higher prevalence than traditionally described among patients with HFrEF and underscores the importance of heightened clinical suspicion regardless of ejection fraction when considering ATTR-CA. Furthermore, although comorbidities are similar, patients with HFmrEF and HFrEF have worse symptom burden.



Transthyretin Cardiac Amyloid: Broad phenotypic spectrum and implications for diagnosis PB65 (#161)

We invite you to attend the XIX International Symposium on Amyloidosis to be held in Rochester, MN.

This symposium is organized as a hybrid meeting (with the focus on in-person) held from Sunday, May 26 through Thursday, May 30, 2024.

Together with the ISA Board and members of Mayo Clinic, a very attractive scientific hybrid program is being planned. The program will cover a variety of types of systemic amyloidosis: ATTR (hereditary and wild-type), AL (light-chain), AA and less frequent forms. There will be key lectures, specific symposia including those company sponsored, oral presentations and poster sessions of accepted abstracts.

COURSE DESCRIPTION
This program will provide a comprehensive review of state-of-the-art education in systemic amyloidosis: basic science, pathophysiology, diagnosis, current and emerging treatments. Scientific presentations will include competitive oral and poster abstracts. The rapid evolution of scientific discovery and expanding treatment options has created tremendous interest in the field and this meeting will fill and important gap in educating scientists and clinicians.